1. Field of the Invention
The present invention relates to a connecting rod for use in reciprocating motion systems such as reciprocating internal combustion engines and a method for producing the same.
2. Description of the Prior Art
There are conventionally known such connecting rods for connecting a piston with a crankshaft in a reciprocating motion system, which include a larger diameter end portion broken and divided into a body side bearing half and a bearing cap, for example, as described in Japanese Patent Application Laid-open No. 37311/83.
In the production of such connecting rods, it is a conventional and common practice to make notches only in the axially opposite end surfaces of a larger diameter end portion of a product of connecting rod resulting from the forging of a blank, at which notches the larger diameter end portion is to be broken and divided into sections, and then subjecting the notched part of the larger diameter end portion to a carburizing and quenching treatment for hardening. Thereafter, the resulting larger diameter end portion is broken and divided into a body side bearing half and a bearing cap, which are subsequently clamped together by connecting bolts, and the larger diameter end portion is subjected to the finishing of its bearing hole. After such finishing, however, when split bearing metals are intended to be assembled to the respective semicircular bearing surfaces of the body side bearing half and the bearing cap, the reverses of the bearing metals may hit against the inner sharp edges of the broken and divided surfaces of the body side bearing half and the bearing cap and consequently, the reverses may be damaged or cut. In addition, the cut powder resulting from such cutting may remain on the broken and divided surfaces, which is apt to deteriorate re-assemblability of the larger diameter end portion.